The Effect of the combination of active vestibular interventions and occupational therapy on Balance in Children with Bilateral Spastic Cerebral Palsy: A pilot randomized Controlled trial

Objective The current study aimed to examine the effect of the combined administration of active vestibular interventions and occupational therapy on balance and the relationship between balance changes and Activity of Daily Living in school-aged children with cerebral palsy (CP). Materials & Methods Twenty-four children with Spastic CP, at the level I and II (according to the “Gross Motor Function Classification System) aged 7-12 years were enrolled and randomly assigned into control and intervention groups. Pediatric Balance Scales and Bruininks-Oseretsky Test of Motor Proficiency II were employed to assess the functional balance changes as well as Force Plate (eyes closed and open) to assess changes in the parameters of balance (e.g. center of pressure excursion). The activity of Daily Living was assessed by “Activity Scales for Kids (performance version)”. Participants in the intervention group received active vestibular intervention for 20 min and a regular occupational therapy program for 25 min. The control group received a regular occupational therapy program for 45 min. Interventions were provided 3 d/week for 6 weeks in each group. The participants were assessed in three stages: baseline, immediately after, and eight weeks after the intervention. Data were analyzed by ANOVA and linear regression. Results The results demonstrated that only functional balance, according to Pediatric Balance Scales scores, was significantly increased in the active vestibular interventions group (p=0.02). There was no significant association between functional balance and Activity of Daily Living (P>0.05). Conclusion The combined administration of active vestibular interventions and occupational therapy could improve the functional balance in children with spastic CP. It may be related to the reorganization of the vestibular system with a controlled and precise application of stimuli.


Introduction
Active vestibular interventions generate through active and volitional head only or whole-body Iran J Child Neurol. Autumn 2020 Vol. 14 No. 4 rotation in the space; and passive vestibular interventions refer to the stimulation in which the subjects play no active role in producing the head or body rotation (8,9). Active vestibular interventions are performed in the context of meaningful, purposeful, and goal-directed activities through sensory feedback derived from the production of adaptive behaviors. Thus, children can meet the "just right" challenge (refers to situations that therapists provide challenges intended to empower children and also to show them that they are able to improve) and learn new movement patterns (10). Active interventions, as compared to passive interventions, appear to be more attractive in children as they can control themselves and predict the movements (10). Therefore, the main aim of this study was to examine the effect of the combination of the active vestibular interventions and occupational therapy on balance, as well as on the Activity of Daily Living (ADL) of school-aged children with bilateral spastic CP in areas of selfcare and dressing.
In this study, it is hypothesized that a combination of active vestibular interventions and occupational therapies can influence the children's balance.
Moreover, these changes would be increased immediately after six weeks and would be maintained for two months after completing the intervention. Also, according to the 'international classification of function, disability, and health' (ICF), function of children with CP is influenced by impairment or limitation in one or more of the body function and structure, activity and participation, so we hypothesized that improving the children's balance would increase their independence in ADL (11).

Materials & Methods
This is a pilot Randomized Controlled Trial, in which one of its arms was blinded (evaluators).

Subjects
In total, 24 children (based on equation1) with bilateral spastic CP participated in this study(10 boys and two girls, average age 8.411± years in the intervention group, and seven boys and five girls, with average age 9.181± years in the control group)   The higher the score, the better the balance ability. Data filtering and COP calculations were performed using the MATLAB software (R2010a).
For data filtering, the AP and ML time series were passed through a fourth-order zero-phase Butterworth low-pass digital filter with a 5-Hz cutoff frequency (13).

Functional balance
The functional balance was tested using the PBS and the balance subtest of BOT-2. PBS comprises 14 items with five ordinary scales options ranging from 0 to 4. Its maximum score is 56, which indicates the highest possible ability (14). The testretest reliability (intraclass correlation coefficient (ICC) >0.95) and inter-rater reliability (ICC = 0.98-1.00) of PBS for CP children were reported as excellent (14). BOT-2 consists of eight subtests: six for the balance skills and three for dynamics, with ordinary scales. The maximum overall score is 36, which indicates the best balance skill (15).
The Inter-rater reliability of the balance subtest was found to be high (r = 0.99). Test-retest reliability, however, was different (15).

Other clinical measurements
The gross motor function was assessed by GMFCS (1). The GMFCS scales contain five distinct motor levels, which children in level I can walk without limitation, and in level V use the wheelchair for transportation (16). Spasticity was assessed using MAS, which ranges from 0 (indicating normal tonus) to 4 (i.e., rigidity), based on the degree of muscle resistance against the passive movement (17).
Changes in functional activities were assessed using the "Activity Scales for Kids performance version" (ASK (before intervention (baseline), immediately after the intervention (after), and eight weeks after completion of the intervention (follow-up)) by two occupational therapists that were blinded to the grouping of the participants (one for laboratory measurements and one for functional and clinical assessments).

Intervention
In the active vestibular interventions group, The interventions were implemented by four occupational therapists that were trained through two sessions and were blinded to the grouping.

Results
Out of 81 children with CP (Figure 1), 24 were able to participate in the current study and were randomly divided into intervention and control groups (10 boys and two girls, with a mean age  Table 2).
The results of the ANOVA indicated that balance scores were improved after providing the intervention ( PBS, BOT-2). Also ASK scores were enhanced in each group ( baseline, after the intervention, and Follow-up) are described in (Table 4).
The results of correlation analysis using mean differences between baseline and follow-up tests ( were not considered for further analysis.  Iran J Child Neurol. Autumn 2020 Vol. 14 No. 4

In Conclusion
According to the results, the combined use of active vestibular intervention and occupational therapy led to better balance than the sole administration of occupational therapy in children with CP. This improvement is quite limited, as only the PBS increased significantly more in the active vestibular intervention group. Furthermore, the intervention resulted in a higher increase in the "ASK" score in the control group. However, the improvement in the "ASK" score was not directly/linearly related to the improvements in the balance. We cannot claim the sole influence of the active vestibular intervention on the children's performance. Therefore, it is recommended that future research not only investigate the effect of vestibular intervention alone on the children's function but also compare the differences between active and passive vestibular intervention in these children with a larger sample size.